<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <button>发送请求</button>
    <br />
    <button>取消发送</button>
    <script>
      var btns = document.querySelectorAll('button')
      let xhr = null
      btns[0].onclick = function () {
        xhr = new XMLHttpRequest()
        xhr.open('get', 'http://127.0.0.1:8080/delay')
        xhr.send()
      }
      // 取消发送
      btns[1].onclick = function () {
        xhr.abort()
      }
    </script>
  </body>
</html>
